Stationary Source GHG Emissions from Petroleum Refinery Operations:

Implications for Higher Level Ethanol Blends

February 17, 2016 National Ethanol Conference

New Orleans, LA

Dr. Vincent Kwasniewski President

Confluence Consulting LLC

Objective

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Moving to higher level ethanol blends: what would be the impact on stationary source emissions of greenhouse gases from oil refineries?

The Broader Context

3 Data Source: M. Wang, et. al. (2014)

12% of the GHG emissions

“LCA Stack”

-13

4

31

4

14

10

9

Bio-refining

Transportation

Transportation

Combustion

Farming

Fertilizer N2O

Fertilizer Production

Land Use Change

60 gCO2eq/MJ

73.3

11.2

5.5

Combustion

Refining

Crude Recovery

Transportation

93 gCO2eq/MJ

Refinery BOB

Fuel Ethanol (from corn starch)

N

E

T

Natural Gas & Utilities

Reformer

Isomerization Unit

Alkylation Unit

BOB Blending

Catalytic Cracking Unit

Model PADD 2 Refinery

4

D

I

S

T

I

L

L

A

T

I

O

N

Crude

Distillate Hydrotreater

Gas Oil Hydrotreater

Coker

Naphtha Hydrotreater

Distillate Blending

Other Products

Petroleum Refinery Planning

5

Profit

Variable B

Variable A

Optimum

• “Linear Programming” (LP) tools & methodology

• Many physical, market, & regulatory constraints

Optimum constrained by A

Min A Constraint

Optimum constrained

by A & B

Min B Constraint

Refinery BOB versus Fuel Ethanol

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Ethanol:

• Single component

• Fixed blending properties

Refinery BOB:

• Many components

• Many refinery streams

• Variable blending properties which vary with refinery, season, and market factors

Composition by component

Fuel Ethanol Refinery A Summer Refinery B Winter

Broad Distribution of Hydro-carbons

Broad Distribution of Hydro-carbons

Gasoline Blending

7

Refinery

BOB

Ethanol

Refinery Stream A

Refinery Stream B

Purchases

Refinery Emissions Study Methodology

• Hypothetical end state where all gasoline contains high levels of ethanol – no transition analysis:

8

E10 base case plus eight “corners” of an octane × ethanol content × gasoline pool volume space

Survey study only - ethanol blend levels and the minimum octane specifications are not to be taken as recommended values

Ethanol Content

Octane Rating

Gasoline Pool

E20 88 AKI Equal Volume

E30 97 AKI Equal Energy

Base Case E10 88 AKI

• 2011 Energy Information Agency projections for 2017 with Oil & Gas Journal published unit capacities

• Modeled with detailed PADD 2 refinery operational planning tools and methodology from Jacobs Consultancy

Refinery Unit Operations Results

• Cat cracker throughput (make less gasoline)

• Reformer throughput (make less octane)

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Max octane:

Current octane:

• Cat cracker throughput ,

but less so (make less gasoline)

• Reformer throughput (make more octane)

Gasoline Blending Results

Low octane requirements Reformate / naphtha

High octane requirements Reformate / naphtha 10

Refinery Greenhouse Gas Emissions

Increased levels of ethanol in finished gasoline resulted in significantly lower GHG emissions in refining

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Refinery Greenhouse Gas Emissions

12

Decreased GHG emissions in refining due to both extensive effects (lower crude run) AND intensive effects (lower

emissions per barrel of crude)

Conclusions and Implications

• GHG emissions caused by the refining process vary significantly with ethanol content and minimum octane specifications in finished gasoline

• Using a fixed GHG emissions intensity for BOB is incorrect ethanol content and minimum octane specifications should also be factors in determining the lifecycle GHG emissions associated with higher level blends of ethanol

• Changes in refinery operations could also have implications for other environmental policies:

• CAFE standards compliance

• Tier 3 compliance (sulfur)

• regulation of stationary source and vehicular toxic air emissions

• possible future stationary source GHG emissions regulations

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Thank You!

Key references on refinery greenhouse gas emissions:

• Kwasniewski, V., Blieszner, J. and Nelson, R. (2015), Petroleum refinery greenhouse gas emission variations related to higher ethanol blends at different gasoline octane rating and pool volume levels. Biofuels, Bioprod. Bioref.. doi: 10.1002/bbb.1612

• Han, Jeongwoo, Elgowainy, Amgad, Michael Wang and Vincent Divita (2015), Well-to-Wheels Greenhouse Gas Emissions Analysis of High-Octane Fuels with Various Market Shares and Ethanol Blend Levels. United States. doi:10.2172/1212715. http://www.osti.gov/scitech/servlets/purl/1212715

• Hirshfeld, D.S., Kobl, J.A., Anderson, J.E., Studzinski, W. and Frusti, J. (2014), Refining Economics of U.S. Gasoline: Octane Ratings and Ethanol Content. Environmental Science & Technology 48, 11064-11071. doi: 10.1021/es5021668

• Speth, R.L., Chow, E.W., Malina, R., Barrett, S.R.H., Heywood, J.B., Green, W.H. (2014), Economic and Environmental Benefits of Higher-Octane Gasoline. Environmental Science & Technology 48, 6561-6568. doi: 10.1021/es405557p

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